916221 has 4 divisors (see below), whose sum is σ = 1221632. Its totient is φ = 610812.

The previous prime is 916219. The next prime is 916259. The reversal of 916221 is 122619.

916221 is nontrivially palindromic in base 16.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 916221 - 2¹ = 916219 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 916221.

It is not an unprimeable number, because it can be changed into a prime (916261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 152701 + ... + 152706.

It is an arithmetic number, because the mean of its divisors is an integer number (305408).

2⁹¹⁶²²¹ is an apocalyptic number.

It is an amenable number.

916221 is a deficient number, since it is larger than the sum of its proper divisors (305411).

916221 is a wasteful number, since it uses less digits than its factorization.

916221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305410.

The product of its digits is 216, while the sum is 21.

The square root of 916221 is about 957.1943376347. The cubic root of 916221 is about 97.1255327278.

The spelling of 916221 in words is "nine hundred sixteen thousand, two hundred twenty-one".